Spacecraft Interaction with Space Plasmas
Dr. Shu T. Lai (Visiting Scientist), Manuel Martinez-Sanchez (Professor)
Kerry Cahoy (Assistant Professor), Whitney Lohmeyer (Ph.D. Student)
Objective of Research
Spacecraft interacts with space plasmas. High-voltage charging of spacecraft affect scientific measurements onboard and may terminate the spacecraft mission. Our objective is to improve understanding of the many aspects of spacecraft charging. It is important to identify possible scenarios of spacecraft charging in the planning stage of space experiments and to provide physical interpretation to the spacecraft charging effects in the data analysis stage of the experimental results. Deep dielectric charging can cause spacecraft anomalies or terminate missions. Mitigation of spacecraft charging is important, especially at MIT where innovation is always a main theme.
Approach / Tools
The basic approach is to better understand the physics of spacecraft charging with space plasmas. The physics is applied to specific systems relevant to space propulsion and spacecraft interacting with space plasmas. When data become available, one analyses the driving factors and the correlating responses in the dynamical behavior of the data. One identifies the critical temperature of the space plasma electrons for the onset of spacecraft surface charging. Abrupt changes in the charging level may cause arcing which can be destructive. In deep dielectric charging, high-energy electrons and ions can penetrate into dielectrics, accumulate inside, and slowly build up high internal electric fields. Electrostatic discharges are likely to occur when the electric fields exceed a critical level. The discharges may cause spacecraft anomalies to occur with delays of hours or days. For mitigation, one endeavors to bring forth original ideas and to do rigorous calculations quantitatively for assessing the feasibility and possible beneficial consequences.
- Lai, S.T., The role of surface condition in the yields of secondary electrons, backscattered electrons, and photoelectrons from spacecraft, IEEE Trans. Plasma Sci., Vol.41, No.6, accepted for publication, (2013).
- Lai, S.T., Spacecraft charging: Incoming and outgoing electrons, Report: CERN-2013-002, pp.165-168, http://cds.cern.ch/record/1529710/files/EuCARD-CON-2013-001.pdf, ISSN: 0007-8328, (2013).
- Lai, S.T., Some novel ideas of spacecraft charging mitigation, IEEE Trans. Plasma Sci., Vol.40, No.2, pp.402-409, (2012). Doi: 10.1109/TPS.2011.2176755.
- Lai, S.T., Fundamentals of Spacecraft Charging, Princeton University Press, Princeton, NJ, 246 pages, ISBN: 9780691129471, hardcover. (2011). http://press.princeton.edu/titles/9500.html
- Lai, S.T., D. Ferguson, M. Cho, L. Eliasson, A. Eriksson, J. Rodgers, J. Sorensen, Spacecraft Charging, S.T. Lai (ed), Progress in Aeronautics and Astronautics Series, 179 pages, AIAA Press, ISBN:978-1-60086-836-8,hardcover, (2011). http://arc.aiaa.org/doi/book/10.2514/4.868375